[Chmellevin]

I took my 2006 VW Jetta TDI in for service and noted that it would vibrate when you come to a complete stop. A shake that you can feel throughout the entire car (with the clutch in or out).

The tech rode with me and suggested the EGR valve might be malfunctioning causing the car to ride rough (thus the shake). They checked the valve, found it to be faulty, and replaced it at no expense to me (thank you warranty).

I'm not so sure it was the EGR valve as the shake is back. Granted it isn't there all the time, but it is back. When I have traveled on the interstate (70-75 mph) it doesn't seem to be present. But once I do some town driving it seems to show up. If I come in on the highway (55-65 mph) it will vary. Is there something with the manual transmission diesel that causes it to shake like that? Any suggestions?

 

[Bluemojo]

All diesels are a little shaky ,especially at shutdown, since the dealer replaced the EGR and it made a difference, there must have been a problem? Coudl it be a wheel bearing or suspension issue?

 

[Chmellevin]

I understand they are a little shaky . . . this is MORE than a little shaky. Originally I thought one of the motor mounts was busted (if that explains how shaky it is).

I would think if it was a wheel bearing I would feel some shaking when the car is moving . . . not sitting idle. Or am I misunderstanding that? I'm not sure about the suspension, but the car was gone through pretty thouroughly prior to coming up with the EGR valve.

 

[chittychittybangbang]

The fact that it's not present on the highway but worst at 55-65 tells me that it's a wheel/axle, etc., issue. Could be a bent wheel or worn axle, something that is rotating and going in and out of sync at that speed is very common.

The engine thing could be unbalanced fuel injectors, one cylinder could be getting fueled differently than the others and causing excess vibration.

I think there was a recall on the EGR so that should have fixed that issue. My car has a bit of a cluck-cluck as the engine shuts off but later years got better.

It's possible that you are having a dual mass flywheel issue. Read about it more here:

http://www.myturbodiesel.com/1000q/clutchfaq.htm

Scroll down to the TSB about the worn clutch/flywheel on sachs clutches. While it's unlikely for the flywheel to be bad so early, it's possible that this is causing a vibration. However, it would be not related to shaking at highway speeds vs faster vs slower.

 

[Stefan2006]

It could be a motor mount. But if the car is still under warranty, the dealer should fix it. If it's happening on the highway, take the mechanic along.

 

[Chmellevin]

Okay . . . maybe I need to rephrase what I am trying to ask!

The car ONLY shakes when it is STOPPED. Ater driving on the interstate I don't notice a shake after coming to a complete stop. After driving on the highway (55-60 mph) it will shake when coming to a complete stop (not turning the engine off - just stopping at the lights). After running errands around town it will shake when I come to a complete stop. The car does NOT shake while traveling, only when stopped. It is more pronounced (upon stopping) if I have driven for quite some distance at the 55-60 mph speed.

When I had it serviced I had the motor mounts double checked as that was my first guess to explain all that vibration while sitting completely still (cluth in or out).

The unbalanced fuel injectors might be a place to start. Thank you!

 

[chittychittybangbang]

Okay, it's possible that the timing is off. I threw the clutch/flywheel thing out there since it's a possibility but most of the time it is normal. To adjust the timing, see this thread:

http://forums.tdiclub.com/showthread.php?t=215202

The idea is to adjust the timing at the camshaft sprocket. You must have a vag-com and adjust it back and forth until you find a spot which works. If it's under warranty, the dealer should do this.